Analysis of 58Ni(n, α) reaction cross sections with the Hauser-Feshbach statistical theory and the bayesian parameter estimation method

Experimental data of 58Ni(n, α) reaction cross sections are analyzed with the Hauser-Feshbach statistical model with the width fluctuation correction by Moldauer. A neutron optical potential which was derived from neutron elastic scattering data is used for an entrance channel in order to fix the total reaction cross sections at reliable values. Global optical potentials are used for the proton and α-particle emission channels, and level density parameters of the residual nuclei are determined from the cumulative plot of discrete levels. These parameters are adjusted to the experimental data of 58Ni(n, α) and (n, p) reaction cross sections, including the angular distribution of the emitted α-particles. The parameters thus obtained yield a good fit to the experimental cross sections of those reactions up to 8 MeV. (author)